Industrial Grade Resin as Reusable Catalyst for Amidoalkylation of γ-Hydroxy Lactams

Herein, we disclose a selective, versatile, accessible, cost-effective and highly efficient cation-exchange industrial grade INDION 130 resin as a reusable catalyst for the synthesis of 3-substituted isoindolinones from various γ-hydroxy lactams and a variety of C, N, O, and S nucleophiles involving N-acyliminium ion intermediates under mild reaction conditions. Mechanistic studies suggested the generation of a different kind of kinetically and thermodynamically controlled intermediates/eliminated products, which further converted to their corresponding products depending upon the nucleophile, reaction parameter and nitrogen substitution (benzyl vs. aryl) of the substrate (succinamidals vs. phthalimidals). The easy synthesis, efficient reactivity and selectivity, broad substrate scope with verities of C, N, O, and S nucleophiles, and efficient recycling make the catalyst and the protocol economical and sustainable.